Breech mechanism for machine-guns.



A. W. SGHWARZLOSE.

BREEGH MECHANISM FOB. MACHINE GUNS.'

APPLICATION FILED PEB.6, 1912.

Patented Sept. 9, 1913.

2 SHEETS-SHEET 1.

A. W. SGHWARZLOSE.

BREBOH MECHANISM FOR MACHINE GUNS.

APPLIUATION FILED rmm, 1912.

1,072,997. Patented Sept. 9, 1913. 132 9%.

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jw/ Wdrms %/%a//77 xYMMCw-" My? ANDREAS WILHELM SCHWARZLOSE, OF GHARLOT'IENIIB'FRG, GERMANY.

BREECH MECHANISM FOR MAGHINE-GUNS.

Specification of Letters Patent.

Patented Sept. 9, 19i3.

Application filed February 6, 1912. Serial No. 675,820.

To all whom it may concern Be it known that I, ANDREAS WILHELM S-crrwARzwsE, a subject of the German Emperor, and resident of Charlottenburg, Germany, have invented certain new and useful Improvements in Breech Mechanisms for Machine-Guns, of which the following is a specification.

This invention relates to a breech mechanism or action for machine guns of that kind in which the firing pin when the shot is fired, slides freely back in the breech casing under the action of the recoil or the pressure of the gases and consequently is not positively moved and tensioned by levers or hinges.

The new invention consists in that when the shot is fired the breech block and the firing pin first move backward together whereafter the firing pin separates from the breech block and owing to the momentum accumulated therein continues alone its rapid backward motion as soon as both parts have moved backwards. little more than the length of a cartridge. By this motion of its own the firing pin by compressing the firing spring not only imparts to it the tension necessary for firing, but also places itself at the same time with its cocking shoulder behind a shoulder of the breech block which keeps it in a cocked condition until the shot is fired. For this purpose the pin in the last part of its retrograding motion performs a supplemental transverse motion during which it slides itself in such a manner into a wedge shaped milled out part of the breech block, that after both parts have flown forward together, it also imparts the locking motion tothe breech block under the action of the main spring.

The trigger mechanism of the gun allows of single and continuous firing. This mechanism is characterized by an increased simplicity not only of construction but also of working, it only comprising a single member which allows without any adjustment of single shots being fired or continuous firing being carried out. Besides the firing pm and the trigger are at once put at safety again when the trigger is released. The trigger mechanism comprises to this end a sear adapted to perform a longitudinal shiftingas well as at the same time a rotary motion and which comprises means to release the firing pin at the moment of firing either by means of an incline provided at its rear part and producing continuous firing or by means of a surface with a straight shoulder adapted to fire single shots. In the position of rest the sear is locked with the fire arm automatically and without the interposition of special coupling members in such a mannerthat it cannot be rotated and that consequently the firing pin cannot be released. Compared with the automatic trigger safety devices known until now the new one has besides the greater simplicity the advantage that the gunner can manipulate the trigger continuously with one hand while formerly both hands were required for this purpose.

The accompanying drawings given byway of example, show two forms of embodiment of the invention and in these drawings:

Figure 1 is a vertical longitudinal section through the breech casing of a machine gun, the breech mechanism being closed the shot fired, the soar in the position for continuous firing and pushed forward. Fig. 2 shows the same section the breech mechanism being entirely o n. Fig. 3 is a cross section on line A of Fig. 1. Fig. 4 shows the same section, the scar being adjusted for single firing. Fig. 5 shows the safety arrangement of the fire arm. Figs. 6 to 8 show various views of the breech block, the firing pin and the sear. Fig. 9 is a modification of the trigger mechanism shown in Fig. 3. Fig, 10 is a modification of the trigger mechanism shown in Fig. 4. Fig. 11 is a modification of the trigger mechanism shown in Fig. 5. Fig. 12 is a rear elevation of the breech casing.

The drawing shows the trigger mechanism combined with a machine gun having a barrel adapted to slide back a short distance and a rotary cylinder closing mechanism; it may however be applied without changing the essential features of the invention also to fire-arms with a stationary barrel and to fire-arms having breech mechanisms of other types,

. ward motion.

When the shot is fired, the barrel lowing to the recoil slides backward in a rectilinear course a short distance in the breech casing h. In this motion it carries with it the breech block 4) which is in locking engagement with it as well as the firing pin 6 which in turn tensions the main spring 7 which bears against the dish shaped end 12 of the firing pin while its rear end bears against the grip member 9. During the backward motion of the barrel the breech block is rotated in the well known manner around its longitudinal-axis by means of levers or inclines to such an extent that its locking studs w leave their bearings provided in the barrel, whereafter the latter stops while the breech block together with the firing pin continue alone their rear- When thereafter the cartridge opening p (Fig. 2.) has been uncovered, the breech block is caught in turn in the breech casing by any desired stopping device. Then the firing pin separates from the breech block and owing to the stored up momentum flies back into its rearmost-posi-v tion (Fig. 2). During this backward motion the dish shaped end of the pin is guided in a rectilinear course by the projections b 6 which move in longitudinal grooves h if of the breech casing. During the last part of the motion the projection b strikes against the inclined surface it of the groove h whereby the rear end of the pin is pressed downward so that its shoulder places itself behind the end surface 0 of the breech block. Now, when after the counter-pressure has ceased, the main spring throws the firing pin again forward, this pin also pushes the breech block, toward the barrel which. in the meanwhile has been moved forward by a special member into the shooting position. During the last part of this motion the wedge surfaces Z of the barrel (Fig. 2) rotate-the breech block slightly toward the right during which motion its straight end surface o 'slides from the shoulder b of thepin. This shoulder is her.

now positioned behind and in engagement with the wedge surface 42 of the breech block which stops at that moment and is thereupon rotated toward the right by the pin continuing flying forward, thus producing again the interlocking engagement between the barrel and the breech block.- The firing pin is then caught by the front surface o (Figs. 5 and 6) of the wedge shaped notch o and is held in cocked position until the shot is fired.

The sear a (Fig. 8) is supported at the front by the trunnion a in a bore of the breech casing and at the. back by the ring a engaging a hole bored into the grip memward by the pressure disk at for firing and The sear can be moved slightly for-' during this motion it tensions the main or closing spring 1 which constantly pushes the sear backward when it is released. The pressure plate or knob allows of the sear being rotated into two working and one safety position. .When the sear is turned to the left and when it is pushed forward for firing (Fig. 3) its firing lug a is turned within reach of the firing stud, it is again raised by the risingsurface a of the stud and once more' released for firing. This operation is repeated as long as the sear is pressed forward.

When it is desired to fire separate shots,.

the sear is rotated toward the rightv (Fig. 4)

When the sear is then pushed forward the stud a is then raised in the same manner as if it were adjusted for continuous firing and the firing pin is released for firing. If however the firing in after the loading motion has been per ormed again comes within the reach of the firing stud, it slides with its notch 12 over the stud thus-preventing the latter from releasing it automatically. It is only after the'sear has been released and has again been pushed backward by the spring, 7, the firing stud is pushed downward in such a manner that when the sear is again pushed forward, it

places itself under. the firing bolt and releases the latter.

Forsafety purposes the sear-rod is rotated in such a manner that the firing stud 0. takes up a position between the two working positions 2'. e. is polnt-ing vertically upward (Fig. 5)., In this position the lug a slides with a recess provided at its front surface in such a manner on a rearwardly projecting h'e'el b of the firing pin disk that the latter cannot be tilted upward and that the shoulder b of the pin cannot be withdrawn from the cooking shoulder a of the breech block.

of the breech casing. In this instance the sear c has two firing studs 0 and 0 which are positioned in diametrically opposed re? lation and the one of which releases the firing pin for continuous firing while the second only serves in 'case separatenshots are to be fired. In the place of the pressure disk orknob a this sear rod is actuated-by a double handle 0 (Fig. 12) provided at the rear end thereof. When, the fire arm being cocked, the sear is rotated toward the right by pressing down the handle 0 (Fig. 12, dash and dot lines) the stud c (Fig. 9) moves upward and lifts the disk 6 of the firing pin to such an extent that the shoulder 6 of the pin is disengaged from the breech block whereafter the main or closing spring f throws the firing pin forward and fires the cartridge. As the stud c is pro.- vided at its rear upper part with an incline similar to that" of the stud a of the first described form of embodiment, the firing pin is automatically released at every closing of the breech i. 6. continuous firing is produced as long as the sear is pressed to ward the right by the gunner.

When it is desired to shoot separate shots the sear is rotated toward the left by means of the double handle 0 whereby the right hand stud c is caused to oscillateupward, to raise the disk 6 of the firing pin and to disengage the latter for firing purposes. Now, the rear end of the stud 0 is not provided with an incline at its top but is cut away square. Consequently, when the firing pin after the loading movement has been carried out automatically, strikes again with its disk 6 against the stud c the pin is not raised and disengaged from the breech block but it carries the stud and consequently also the sear a short distance with it forward (Fig; 10). For firing the next shot, the sear is first turned backward to its central position (Fig. 12) by means of the double handle 0 whereafter the main spring f which by the forward motion of the sear had been slightly tensioned, again pulls the sear back whereby the studs 0 c are again brought under the disk of the firing pm. By pressing the double handle 0 down toward the right or toward the left, one is enabled to indulge either incontinuous or separate firing. In this form of embodiment the cocked firing pin is also provided with a continuous safety device. To this end, thesear carries besides the two firing studs 0 and 0 still a special safety stud 0' (Figs. 9 and 11). When the sear assumes its position of rest, the safety stud projects vertically upward and a depression provided in its rear end is positioned in such a manner in front of a heel I), provided on the disk of the firing pin that the latter is prevented from being tilted upwardly. Besides, in this central position, the main spring 7 brings a lug on the sear continuously back into a notch 9 (Fig. 12) of the breech casing or of the grip member g, so that the scar is prevented from beingrotated by accident. For firing, the sear must therefore be pushed a little forwari before being rotated so that it becomes disengaged from the notch 9 During this motion, its safety stud 0 also slides from the firing pin so that the latter can be raised by the studs 0 or 0 In order to prevent the firing pin, when it is thrown forward together with the breech block and when the latter is locked, from sliding too early upward from the breech block, it is provided with two guide studs 6' (Figs. 7, 9 and 10),. The latter, When the firing pin performs its transverse motion and occupies its rearmost position (Fig. 2) engage a longitudinal groove 7& which is undercut on both sides in the breech casing (Figs. 9 and 11) and which releases the pin upward only in the cocked position (Figs. 5 and 11), the groove being cut open at this spot for this purpose and changing into the longitudinal bore for the 'main spring.

Having now. fully described my said invention, what I claim and desire to secure by Letters Patent, is:

1. In a breech mechanism the combination with a breech casing of a breech block, a firing pin, a sear, this sear carrying a releasing member having a rear incline and a releasing member, having a rear straight surface, both releasing members being adapted to engage and release said firing pin, the releasing member with the incline being adapted to release the pin at every closing of the mechanism and produces continuous firing, while the said straight surface again positively engages the firing tpin only when the sear has been released a ter the shot or that separate firing is obtained substantially as set forth.

2. In a breech mechanism for machine guns the combination with the breech casing of a firing in, a scar adapted to be rotated toward the left and the right, means for holding the said firing pin in the cooked position, two diametrically opposed releasing studs provided on said sear so as to be under the said firing pin when the latter is cocked, each of these studs being adapted on rotation of the sear to release the firing pin, one of said studs having an inclined rear part and the other a straight rear surface, substantially as and for the purpose set forth.

3. In a breech mechanism for machine guns the combination with the breech casing of a firing pin, means for cocking the firing pin, a scar adapted to be rotated toward the left and the right, a notch in said casing, and yielding means for automatically causing the said sear to engage said notch when in its position of rest, so that any rotation of the sear is prevented and that the firing pin cannot be disengaged, substantially as and for the purpose set forth.

4. In a breech mechanism for machine guns the combination with the breech casing ing the cocked position, substantially as and of a firing pin, means for cocking the firing for the purposev set forth. 10 pin, a scar, a safety stud on said sear, means In testimony whereof I have hereunto set for continuously-pushing the sear backward, my hand in presence of. two witnesses.

the said safety stud being adapted, when ANDREAS WILHELM SOHWARZLOSE. the sear is released and pushed back to en- Witnesses: gage from the front the firing pin thus pre- HENRY HAsPER,

venting the latter from spontaneously leav- WOLDEMAR HAUPT. 

